Comment Log Display

Further comments on proposed regulation;

1.   ASTM Standard E1333 is inappropriate for the regulation. The
sensitivity of the test is intended to be appropriate to determine
airborne concentrations in the range of 0.3 ppm. The proposed
regulations would limit concentrations to values as low as 0.05
ppm. A more sensitive test is required for compliance. I suggest
eliminating the chromotropic acid analytical method and using only
DNPH for the analysis described in the standard. It must be
recognized that E1333 was written for compliance with the HUD
standard which limits concentrations to 0.3 ppm. DNPH is included
as an alternate in the standard, but it should be the required
method. There is an ASTM standard for the DNPH method.

2.   I do not  believe that the final regulatory targets in years
2011 and 2012 of 0.11 and 0.13 for MDF and thin MDF respectively
are sufficiently protective of the population. The installation of
products with these emissions in residential bedrooms of energy
efficient homes - tightly sealed against air leakage and without
any specific outdoor air ventilatioon system -- where ventilation
rates may be significantly lower than the 0.5 air changes per hour
in the test chamber means occupants will be exposed to
concentrations well in excess of 0.1 ppm. Given the abundant
evidence of the toxicity and the listing of formaldehyde as a
carcinogen, I believe the limit should be based on a target
concentration no higher than that established by OEHHA for
workplace exposure which is only intended to protect workers
during a 40-hour work week. Far more time could be spent in a
residence thus requiring a far lower target concentration or
concentration limit.
3.    I recommend a concentration target limit that is based on an
assumption of 0.25 air changes per hour and an emission rate that
does not result in concentrations exceeding 0.027 ppm formaldehyde
under realistic modeling scenarios. Assume MDF will be the core of
a composite flooring material with a loading ratio of 0.42 m^2/m^3
and cabinetry or closet doors with a loading ratio of 0.25 m^2/m^3.
An emission rate far below the proposed limits will be required to
provide protection in energy efficient residential environments
with typical ventilation rates below 0.5 air changes per hour.
Even at 0.5 ach, concentrations of 100 ppb or above are simply
unacceptable given the health effects data on formaldehyde
exposure.

Hal Levin
Building Ecology Research Group
2548 Empire Grade, Santa Cruz, CA 95060
1.831.425.3946